To improve the impeller milling efficiency, the zero-order analytical method to construct the milling stability lobe diagram is investigated, which is used to determine parameter optimization of the FV520B material milling. The appropriate number of revolutions and the cutting depth processing can be selected, and the chatter occurrence can be avoided. By using this method, the required accuracy and surface quality for the workpiece can be achieved, and tool safety and machine reliability can be maintained. Through experimental data analysis, the parameters to construct the lobe diagram can be obtained. Different testing points in the constructed lobes are used to verify the method’s correctness. This method has great significance in the actual impeller manufacturing process.